def test_high_dimension_memmap_array_reducing(tmpdir): assert_array_equal = np.testing.assert_array_equal filename = tmpdir.join('test.mmap').strpath # Create a high dimensional memmap a = np.memmap(filename, dtype=np.float64, shape=(100, 15, 15, 3), mode='w+') a[:] = np.arange(100 * 15 * 15 * 3).reshape(a.shape) # Create some slices/indices at various dimensions b = a[0:10] c = a[:, 5:10] d = a[:, :, :, 0] e = a[1:3:4] # Array reducer with auto dumping disabled reducer = ArrayMemmapForwardReducer(None, tmpdir.strpath, 'c', True) def reconstruct_array_or_memmap(x): cons, args = reducer(x) return cons(*args) a_reconstructed = reconstruct_array_or_memmap(a) assert has_shareable_memory(a_reconstructed) assert isinstance(a_reconstructed, np.memmap) assert_array_equal(a_reconstructed, a) b_reconstructed = reconstruct_array_or_memmap(b) assert has_shareable_memory(b_reconstructed) assert_array_equal(b_reconstructed, b) c_reconstructed = reconstruct_array_or_memmap(c) assert has_shareable_memory(c_reconstructed) assert_array_equal(c_reconstructed, c) d_reconstructed = reconstruct_array_or_memmap(d) assert has_shareable_memory(d_reconstructed) assert_array_equal(d_reconstructed, d) e_reconstructed = reconstruct_array_or_memmap(e) assert has_shareable_memory(e_reconstructed) assert_array_equal(e_reconstructed, e)
def test_memmap_based_array_reducing(tmpdir): """Check that it is possible to reduce a memmap backed array""" assert_array_equal = np.testing.assert_array_equal filename = tmpdir.join('test.mmap').strpath # Create a file larger than what will be used by a buffer = np.memmap(filename, dtype=np.float64, shape=500, mode='w+') # Fill the original buffer with negative markers to detect over of # underflow in case of test failures buffer[:] = -1.0 * np.arange(buffer.shape[0], dtype=buffer.dtype) buffer.flush() # Memmap a 2D fortran array on a offseted subsection of the previous # buffer a = np.memmap(filename, dtype=np.float64, shape=(3, 5, 4), mode='r+', order='F', offset=4) a[:] = np.arange(60).reshape(a.shape) # Build various views that share the buffer with the original memmap # b is an memmap sliced view on an memmap instance b = a[1:-1, 2:-1, 2:4] # c and d are array views c = np.asarray(b) d = c.T # Array reducer with auto dumping disabled reducer = ArrayMemmapForwardReducer(None, tmpdir.strpath, 'c', True) def reconstruct_array_or_memmap(x): cons, args = reducer(x) return cons(*args) # Reconstruct original memmap a_reconstructed = reconstruct_array_or_memmap(a) assert has_shareable_memory(a_reconstructed) assert isinstance(a_reconstructed, np.memmap) assert_array_equal(a_reconstructed, a) # Reconstruct strided memmap view b_reconstructed = reconstruct_array_or_memmap(b) assert has_shareable_memory(b_reconstructed) assert_array_equal(b_reconstructed, b) # Reconstruct arrays views on memmap base c_reconstructed = reconstruct_array_or_memmap(c) assert not isinstance(c_reconstructed, np.memmap) assert has_shareable_memory(c_reconstructed) assert_array_equal(c_reconstructed, c) d_reconstructed = reconstruct_array_or_memmap(d) assert not isinstance(d_reconstructed, np.memmap) assert has_shareable_memory(d_reconstructed) assert_array_equal(d_reconstructed, d) # Test graceful degradation on fake memmap instances with in-memory # buffers a3 = a * 3 assert not has_shareable_memory(a3) a3_reconstructed = reconstruct_array_or_memmap(a3) assert not has_shareable_memory(a3_reconstructed) assert not isinstance(a3_reconstructed, np.memmap) assert_array_equal(a3_reconstructed, a * 3) # Test graceful degradation on arrays derived from fake memmap instances b3 = np.asarray(a3) assert not has_shareable_memory(b3) b3_reconstructed = reconstruct_array_or_memmap(b3) assert isinstance(b3_reconstructed, np.ndarray) assert not has_shareable_memory(b3_reconstructed) assert_array_equal(b3_reconstructed, b3)